CAT5 unshielded twisted pair cable terminating in an RJ45 modular connector is typically used for local data transmissions, such as the 100 Mb Ethernet local area network (LAN). Prior art regarding RJ45 connectors with integrated signal-conditioning magnetics for 100 Mb Ethernet applications is bountiful. Examples thereof include U.S. Pat. Nos. 5,971,813 and 6,171,152. But, to my knowledge, none can provide Class B electromagnetic interference performance with unshielded CAT5 cable. Class B is a conducted and radiated emissions standard of the FCC Part 15 in the US and of CISPR 22 internationally. Some of the existing connectors can provide Class B performance with shielded CAT5 cable. But shielded cable is expensive and therefore not widely used. For example, the cabling infrastructure of most businesses uses unshielded CAT5 cable to make data connections to employees' desktops.